It uses factory-reject chips and has more than 220,000 defects, each of which could kill a lesser machine. But this supercomputer, known as Teramac, could be the forerunner of faster, cheaper, and more powerful chemical computers.
Teramac's defect tolerance could theoretically help engineers build smaller computers using chemistry -- something necessary for innovation in the field to continue, researchers said in a report published in the journal Science.
"This is another path to hopefully continue the computer revolution," Philip Kuekes, a computer architect at Hewlett-Packard Laboratories in California, who helped build Teramac, said in an interview today.
"Chemistry allows you to build very small things on an atomic scale even if they aren't perfect. We believe we can build smaller-sized computer circuits using chemical reactions."
Current silicon technology, which uses light to produce chips, has its limitations. When wavelengths become too short they turn into X-rays and damage molecules. "We can't keep going in that direction because we will eventually destroy what we are trying to build," Kuekes said.
But making components chemically allows engineers to shrink the size of circuits. This means faster machines.
"The signals don't have as far to go and are much faster," Kuekes said.
Teramac, for example, has more connections than normal computers and for certain applications was 100 times faster than Hewlett-Packard's top workstation, Kuekes pointed out.
The computer was able to disregard the flaws because its makers set up the wires and connections in a way similar to a series of city streets with no dead ends. This let Teramac find its own solution by routing around defects by choosing a different pathway.
Using chemistry to make defect-tolerant computers will also help lower the skyrocketing costs it takes to manufacture the chips needed to run computers, the researchers said.
"Today, [chips] have to be perfect. The significance is it will drop the cost if they don't have to be," Kuekes said.
A large part of the expense in manufacturing microprocessors today is the multibillion-dollar plants, where the cost of making perfect devices requires increasing cleanliness and precision. But with defect-tolerant computers, these plants merely become costly overkill.
"As perfect devices become more expensive to fabricate, defect-tolerance becomes a more valuable method to deal with imperfections," the researchers wrote in Science.
Jim Heath, a chemist at UCLA who worked on the study, said building a computer chemically lets researchers design computers that exceed the limitations of silicon-chip technology.
"Theoretically, computers can be much more efficient ... but you're not going to do it with silicon technology," he said in an interview.
Actual construction of computer in a chemical lab is at least 10 years away, but Heath said Teramac's success "suddenly gives people in the field a goal."
